Dry eye syndrome, known medically as keratoconjunctivitis sicca, is an umbrella term for a condition of severely dry eyes caused by a lack of proper tear production and distribution. (Re- cently, some experts have recommended that the label ‘‘dry eye syndrome’’ be changed to ‘‘dysfunctional tear syndrome.’’ The term ‘‘dry eye syndrome’’ connotes different things to both phy- sicians and to patients, and ‘‘dysfunctional tear syndrome’’ is considered by some experts to be more consistent with the basic issue, which is the diminished quality and quantity of tears. The term ‘‘dry eye’’ suggests that dryness is present in all patients, which is not necessarily the case. Still, for the purposes of this book, I have chosen to call the disorder by its best-known label: dry eye syndrome.)
Basically, dry eye syndrome manifests in one of two ways: aqueous tear deﬁcient dry eyes or evaporative dry eyes. Aqueous tear deﬁcient dry eye develops because the lacrimal (tear) glands, located under the eyelids, do not produce enough tears to keep the surface of the eye sufﬁciently moist. Evaporative dry eye results from an abnormality in tear composition causing the tears to evaporate too quickly.
If you have dry eye syndrome, you are well aware that it can be extremely painful and cannot be cured by such techniques as eye laser surgery. In addition, dry eye syndrome impedes vision by generating blurriness and visual distortion. Glasses don’t help because the problem lies with the physical dryness. Contact lenses don’t help; in fact, they may make the situation worse because contact lenses need the lubrication of tears to work effectively. Without sufﬁcient tears, contacts often feel like they’re painfully glued onto your eyes—as if you are wearing a salty potato chip instead of a contact lens.
Dry eye can severely affect virtually every aspect of your life, from the simplest everyday occurrence to the progress of your career. Experts have found that, with severe dry eye, the decrease in the quality of life is comparable to that among patients with severe angina or a disabling hip fracture. For example, many patients with dry eye syndrome must plan ahead carefully be- fore embarking on the most simple everyday activities, from going to a movie or play, to enjoying dinner in a restaurant, even to riding in a car. They must be sure their eyes are sufﬁ- ciently lubricated and that they avoid sitting near a heating duct, air-conditioning unit, fan, or any other place where the ambient air is agitated. Not surprisingly, severe dry eye sufferers should avoid smoke-ﬁlled rooms and socializing with smokers. They even need to think about the weather as it pertains to their eyes, since wind, rain, and dry or cold conditions affect chron- ically dry and irritated eyes.
Many patients with dry eye syndrome are dismayed by their deteriorating appearance, for their eyes can often be red and even teary. Often family members, friends, and colleagues begin to notice the sufferer’s red, irritated eyes. While most people will be sympathetic, others (one’s boss, for example) may mistakenly conclude that the person with the bloodshot eyes must have a serious drug or alcohol problem.
Most seriously, a moderate to severe case of dry eye syn- drome can affect the quality of one’s work and ultimately the progress of one’s career. This is particularly true for anyone who spends several hours each day working on a computer terminal. In this day and age, that includes many, many workers—from lawyers, bankers, accountants, journalists, and writers, to ofﬁce workers of virtually every stripe. Dry eye can make work that involves the eyes very painful, and, if the dry eye is not dealt with properly, work may become impossible.